Luke, since you will visit Arlo in BC why not repeat the Cross Canada trip that Justin did in 2008 and make it up to Montreal for the Formula-E with your DSR and 18kW charging power! =)) after all that's just 5000km

I'm kidding! as well.. but that would be cool..

Doc

stop by my place along the way for a BEvERage too!

alro, skimming over your tire spin problem.. i wonder if your controller would benefit from addition of torque control. this is not current control, not speed control, not position control (which shouldn't be in your controller).. its torque control. just another loop really, can be open loop as you probably don't ahve a torque sensor. its useful for detecting tire spin and doing something about it. just a thought.

Luke, since you will visit Arlo in BC why not repeat the Cross Canada trip that Justin did in 2008 and make it up to Montreal for the Formula-E with your DSR and 18kW charging power! =)) after all that's just 5000km

I'm kidding! as well.. but that would be cool..

Doc

stop by my place along the way for a BEvERage too!

alro, skimming over your tire spin problem.. i wonder if your controller would benefit from addition of torque control. this is not current control, not speed control, not position control (which shouldn't be in your controller).. its torque control. just another loop really, can be open loop as you probably don't ahve a torque sensor. its useful for detecting tire spin and doing something about it. just a thought.

Thats a cool way to do it... Find max torque and stay there. So even with spinning slicks (which need like 30% slip or something) it will find the max torque and try to hold it.

Anyways the plan is to add a comparison from the rear wheel speed to the motor rpm and let the motor rpm go X % faster then the rear then PWM the throttle to reduce the power...

Having had a look at vids again wearing headphones, I think you might have some damping tweaks to make on the front axle. When running soft sidewall slicks it's somewhat tricky to get the suspension to reduce oscillation as the easiest movement is in the tire. If your shocks are adjustable at all I would back off your damping/rebound considerably and try again. If not then start looking at what the fast honda guys are running as a baseline.

Be cautious when looking at tire choices, I would say your current pair should get you well into the 11's with tweaks. If you go to a taller slick like 25.5 or 26 inch then you're starting to get into axle snapping territory, especially if you haven't got suspension motion and torque delivery dialed in. It might be a good shortcut to quick times, but might be a bit heartbreaking too if you continuously smash shit. I realise that's all part of the journey, but if you're driving the car there and hoping to drive home... bit different than if you've got a trailer and alternatives.

Ohbse wrote:Having had a look at vids again wearing headphones, I think you might have some damping tweaks to make on the front axle. When running soft sidewall slicks it's somewhat tricky to get the suspension to reduce oscillation as the easiest movement is in the tire. If your shocks are adjustable at all I would back off your damping/rebound considerably and try again. If not then start looking at what the fast honda guys are running as a baseline.

Be cautious when looking at tire choices, I would say your current pair should get you well into the 11's with tweaks. If you go to a taller slick like 25.5 or 26 inch then you're starting to get into axle snapping territory, especially if you haven't got suspension motion and torque delivery dialed in. It might be a good shortcut to quick times, but might be a bit heartbreaking too if you continuously smash shit. I realise that's all part of the journey, but if you're driving the car there and hoping to drive home... bit different than if you've got a trailer and alternatives.

Thanks for the tips.

I think what is going on its the front is OVER sprung and the dampening was backed off (I usually crank it which makes it better) But I also have the front strapped down so I think step one is softer springs then keep the straps where they are or lower. And see if I can get rid of that problem with adjusting the dampening. Its Ohlins suspension so its fully adjustable but its from a heavier car so its sprung quite stiff.

I have some things to work on and a bit of a game plan if I could raise the rear a bit it would help as well.

Found some softer springs for the front today it lowered the car about 1" in the front (goal was to lower it about 1/2") I tried driving it though and the spring rate is fine the lowered softer front makes it launch WAY harder on the street tires.

I also replaced a tie-rod end with a bit of play in it and modified the bushings on the front control arms to be stiffer. Re-did the wheel alignment and ordered a set of adjustable camber A arms and a set of adjustable rear toe links as the front camber is at -2.5 deg when 0 deg during acceleration is what you want. The rear wheels are towed out 1/4" so that's scrubbing a bit of speed in the 1/4 but also costing me in range

Excited to make it hook up better at the track while still functioning as a fun sleeper on the streets.

Arlo, I know its not exactly in the scope of this thread but you have poked around a Leaf controller more than most people so you are probably a good person to ask: What kind of power do you think the factory leaf controller is capable of if you replaced its brain with something like http://advantics.fr/umc-drive-3-0-unive ... ontroller/? I'm wondering if it could be a cheap way to use the factory stuff in other chassis and possibly push the limits a bit.

MrJoshua wrote:Arlo, I know its not exactly in the scope of this thread but you have poked around a Leaf controller more than most people so you are probably a good person to ask: What kind of power do you think the factory leaf controller is capable of if you replaced its brain with something like http://advantics.fr/umc-drive-3-0-unive ... ontroller/? I'm wondering if it could be a cheap way to use the factory stuff in other chassis and possibly push the limits a bit.

MrJoshua wrote:Thank you for the quick reply! Assuming the setup isn't battery limited where do you focus your push into the headroom? More amps, more volts, or both? Whats likely to kill the factory guts?

If you study the OEM data they make 80kw at 2000rpm and rate it continuously at 2000 rpm at 80kw as well at higher rpm at 80kw.

The oem 2011 leaf motor makes 210 ft-lbs at 0-2000 rpm then reduces the torque to limit the battery to 80kw.

All you need to do is make the 210 ft-lbs at a higher RPM. Nothing will break torque is what stresses things and the motor current is what makes the torque as well as heats the motor. So if you keep it at the already known to be ok 210 ft-lbs but just let it make that torque at higher rpm everything will be fine, provided you have a battery that can do it.

MrJoshua wrote:Did you ever get a chance to post your dyno graph? I'm trying to get an idea of the voltage needed to carry out that 210 ft lbs high enough in the RPM range to top 200HP.

Its in the video.

I need to email that guy again as he was sending the files over to me....

My files keep crashing his computer. I am heading to a dyno again next week. But its limited to 2250 ft-lbs at the wheels... We will see hot it goes as I know I am right around that.

When I tune it the torque graph will be straight from 0rpm to about 6500 then slowly start to fall With a peak ~ 6500-7500 rpm for HP.

The graph doesnt really tell you....

You will need 250-300hp of battery. You will want the stiffest battery you can get. If you have something better then the oem LEAF it will be better the new leaf cells are 10c peak rated old cells are 3c peak rated.

Trying to get this to post as a pic. Trying out a Amazon after photobucket went nuts.

Edit-Try this:

Very cool! I didn't know endless sphere hosted their own photos. Makes things so much easier! Thank you AmberWolf!

That said-Arlo, you have an interesting motor curve that is unlike most I've seen. You don't have the board flat torque lower rpm part of the curve where you are holding against programmed amp limits but you also don't have the flat power curve I would expect if you are basically giving the motor all the battery can dish out with no limits. It is a beautiful dyno plot with great power over many thousands of RPM, it's just not what I've ever seen from an electric. I love it though. Its like you took a V8 with all it's wonderful torque-and then doubled the size of its lungs.

Last edited by MrJoshua on Aug 16, 2017 6:50 am, edited 3 times in total.

MrJoshua wrote:Trying to get this to post as a pic. Trying out a Amazon after photobucket went nuts.

Edit-Try this:

Arlo Electric CRX Leaf Motor Dyno.jpg

Very cool! I didn't know endless sphere hosted their own photos. Makes things so much easier! Thank you AmberWolf!

That said-Arlo, you have an interesting motor curve that is unlike most I've seen. You don't have the board flat torque lower rpm part of the curve where you are holding against programmed amp limits but you also don't have the flat power curve I would expect if you are basically giving the motor all the battery can dish out with no limits. It is a beautiful dyno plot with great power over many thousands of RPM, it's just not what I've ever seen from an electric. I love it though. Its like you took a V8 with all it's wonderful torque-and then doubled the size of its lungs.

Its not done. I didn't get any actual time on the dyno to properly tune it. The Torque curve will be flat when I get on the dyno next week.
This really wasn't a big deal to post as whats coming is WAY better

So I spent tuesday ballancing the cells under the hood and loading all the things I could into the car including 6 spare IGBTs 4 spare driver boards 3 of which are to be sold to a customer. Loaded 4 extra Zero packs for more power if I got that far. Had 10 fuji 800a IGBTs sent directly to the tuning shop (Malone tuning) and they were over nighted from FUJI usa because the clowns down their sent me 10 of the wrong parts tuesday morning... I put my ocsilloscope and soldering iron in the car an everythign else I could think of. Went home and managed to get to bed at 10pm then got up a 4am to catch a 515 ferry....

Made it to Malone tuning at 8 am and plugged in to charge at my limited of 3kw while we got setup. First we went got a coffee (had 2.5-3hr to kill) then we started bolting the flange adapters to the hubs of the car and find the lug nuts my fancy wheels use dont work... So off to lordco then CDN tire to find a set of standard lug nuts. Back again to finish getting setup...
Finaly once we have it all setup on the dyno packs we try doing what is supposed to simulate a inertia run and the dyno tries to match the load of the motor we tried starting at 500 then 750 then 1000 then 4500 rpm before deciding that wont work as every time it created a horible osilation.
They then had to set it up to read HP at different RPM increments and it was set to spend x amount of time at every increment. This worked but scared me so I let off as it was taking for ever for a run to go from 4000-10000 rpm as we had it entered. We then tried one more and at 7400 rpm it triped a over current in the controller the hardware desat tripped and shut the car down. We let things cool but it would not turn on again... So that was rebuild number one.

Before the 2 main runs and tiny bit of fumbling around it was full at 465v... It took just over 2 hr to charge back up at 3kw to get to 465v Meaning we pulled over 6kwh out beating on it trying to dyno it... Which ended up how long it took me to rebuilt it the first time... From there i turned the power down from 750 phase amps to 450 phase amps thinking it should live for sure. I also tried using the inductance and resistance measuring option in the controller to let it try to measure the motor and it give me a number of 150 uH and 25 mOhm (the numbers I have had working for the 1/4 mile runs and the other dyno days are 60 uH and 20 mOhm) so I tried to make a run from 4k-10k with the new settings and it blew up at ~7400 rpm again. But this time we herd/saw a loud bang when it blew up which was the low side contactor exploading and it hit the hood denting it from the bottom then a big plasma ball and smoke come out. Luke Jackson and everyone said they have never seen that before.

So we shut it down and I disconnected the main disconnect in the middle of the pack to make it safer. I then messaged a couple people who I could think of in the vancouver area to see if they had contactors and Casey Mynott came to save the day. So while we waited for him I rebuilt the controller again this time though it was BAD I have never seen a IGBT blow apart like that and trust me I have killed over 100 IGBTs at this point. At first I was really thinking its the way the Dyno packs work. But Luke pointed out the contactor might have bounced and lost contact for a split second. Which is possible as these contactors have been welded many times and freed up with a hammer... Non the less I got it all working put the old "tune" back into the controller and decided to cut my losses and bolted for the 10:45pm ferry which put me in bed at 2am.... I have to accept the universe doesnt want it to happen that day... Not sure why yet but I will do some more street tuning for now. Its a daily driver and I lay rubber all the time. 7500 rpm is 100kmh and at that speed it doesnt spin the tires with the settings I have been running it at meaning it should not really matter the dyno holding was it there to long.. But I also wondered if it was because there is no inertia meaning the motor could have been slowing or changing speed faster or slower then the controller is used of.
On my way home it run like a top laying rubber at will and passing cars at full power at 100km/h+ so the controller is set well I just know there is more power to be had. Once I get it sorted with the 600a parts I will try the 800a parts again. But I am on a budget as well and need to be cautious. Every time it blows its 2 IGBTs and 1 driver board for sure and thats Min $500 in parts.
The good news is the torque curve is flat with the new inductance/resistance settings so I will try that now that I am at home where its easier to fix.

This is all nothing new to me but I have settings that work amazing on the street and fairly well at the drag strip So I was really astounded that it failed so fast on the dyno.

Pushing forward... As always

-Arlin

Attachments

IMG_20170823_150551990.jpg (93.14 KiB) Viewed 1007 times

IMG_20170823_154808028.jpg (79.59 KiB) Viewed 1007 times

Two runs one with lower power but inductance set higher

IMG_20170823_155354571.jpg (100.36 KiB) Viewed 1007 times

The end of this curve shows the contactor failure. You can see how it looses power as the contactor starts melting.

The inertia run issue was most likely due to the dyno control loop and the your motor drive control loop finding an unfortunate resonance with each other. I wouldn't be surprised if your motor drive can respond much faster to load changes than a dyno typically used for ICE cars (it might not have enough gain/bandwidth). You might have better luck with a Mustang or Dynojet with a load module + you get to use tires (do not dyno on slicks/bias play race tires! They can chunk!).

Using dynos with load cells I've also found it's pretty easy to setup unrealistic loads. I found automatics / boosted setups would sometimes not produce results the same as running down the track or on the street, even with loads that were supposedly accurate representations. Funky numbers (sometimes way low).

I've also seen several issues with dyno operators not knowing enough about what they are doing and don't have the dyno configured properly.

Sorry to hear about the issues, at least you got to drive it home vs flat bed it, so still sorta a win.

zombiess wrote:The inertia run issue was most likely due to the dyno control loop and the your motor drive control loop finding an unfortunate resonance with each other. I wouldn't be surprised if your motor drive can respond much faster to load changes than a dyno typically used for ICE cars (it might not have enough gain/bandwidth). You might have better luck with a Mustang or Dynojet with a load module + you get to use tires (do not dyno on slicks/bias play race tires! They can chunk!).

Using dynos with load cells I've also found it's pretty easy to setup unrealistic loads. I found automatics / boosted setups would sometimes not produce results the same as running down the track or on the street, even with loads that were supposedly accurate representations. Funky numbers (sometimes way low).

I've also seen several issues with dyno operators not knowing enough about what they are doing and don't have the dyno configured properly.

Sorry to hear about the issues, at least you got to drive it home vs flat bed it, so still sorta a win.

Thanks Zombies,

I left in a great mood met some great people saw a different business. My car run mint driving home and regen to a stop at all the lights was amazing. It makes me smile every time I need to slow down knowing I put some energy back in the battery and then I get to launch again

I made progress either way in the big picture this is still moving forward. I know this is not easy stuff and learning how to minimize damage each time something goes wrong is a crucial thing. Likely I will learn how to use the dyno and see what I can do to help set it up next time.

I also set my thermal cuts to start at a lower temp. I will adjust the desat zener to make desat trip a bit easier as well.

zombiess wrote:(do not dyno on slicks/bias play race tires! They can chunk!)

Don't do it on drag radials either. Ask me how I know

Yeah we had a guy here on the island dyno testing his drag turbo hyabusa over and over on a slick it exploded and smacked I'm in the back throwing him forward injuring his back, head and breaking 3 ribs.